-
- if (!sc->order || !(sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM))
- continue;
-
- /*
- * Attempt to take all pages in the order aligned region
- * surrounding the tag page. Only take those pages of
- * the same active state as that tag page. We may safely
- * round the target page pfn down to the requested order
- * as the mem_map is guaranteed valid out to MAX_ORDER,
- * where that page is in a different zone we will detect
- * it from its zone id and abort this block scan.
- */
- zone_id = page_zone_id(page);
- page_pfn = page_to_pfn(page);
- pfn = page_pfn & ~((1 << sc->order) - 1);
- end_pfn = pfn + (1 << sc->order);
- for (; pfn < end_pfn; pfn++) {
- struct page *cursor_page;
-
- /* The target page is in the block, ignore it. */
- if (unlikely(pfn == page_pfn))
- continue;
-
- /* Avoid holes within the zone. */
- if (unlikely(!pfn_valid_within(pfn)))
- break;
-
- cursor_page = pfn_to_page(pfn);
-
- /* Check that we have not crossed a zone boundary. */
- if (unlikely(page_zone_id(cursor_page) != zone_id))
- break;
-
- /*
- * If we don't have enough swap space, reclaiming of
- * anon page which don't already have a swap slot is
- * pointless.
- */
- if (nr_swap_pages <= 0 && PageSwapBacked(cursor_page) &&
- !PageSwapCache(cursor_page))
- break;
-
- if (__isolate_lru_page(cursor_page, mode, file) == 0) {
- unsigned int isolated_pages;
-
- mem_cgroup_lru_del(cursor_page);
- list_move(&cursor_page->lru, dst);
- isolated_pages = hpage_nr_pages(cursor_page);
- nr_taken += isolated_pages;
- nr_lumpy_taken += isolated_pages;
- if (PageDirty(cursor_page))
- nr_lumpy_dirty += isolated_pages;
- scan++;
- pfn += isolated_pages - 1;
- } else {
- /*
- * Check if the page is freed already.
- *
- * We can't use page_count() as that
- * requires compound_head and we don't
- * have a pin on the page here. If a
- * page is tail, we may or may not
- * have isolated the head, so assume
- * it's not free, it'd be tricky to
- * track the head status without a
- * page pin.
- */
- if (!PageTail(cursor_page) &&
- !atomic_read(&cursor_page->_count))
- continue;
- break;
- }
- }
-
- /* If we break out of the loop above, lumpy reclaim failed */
- if (pfn < end_pfn)
- nr_lumpy_failed++;